Just wondering if anyone has an opinion.

I am wanting to buy a new machine for P3D but am stuck between choosing a 4 core I7 7700k @5Ghz or a 8 core I7 7820X @4.6Ghz along with 1080Ti and 16GB Ram.

The I7 7700k @5Ghz build will cost £2,400 and the I7 7820X @4.6Ghz build will cost £2800 from Scan.co.uk £400 difference

I have read that the 7700 is a great chip but have been reading Avsim and P3d hardware forums and it seems the newer x series processors are also very good.

I have also read from Rob Ainscough that L3 Cache is important and the 7820x has 11mb were as the 7700 has 8mb. I have also read from Rob that 7900x is giving great performance too, but I cant stretch to a 7900x only to a 7820x.

I have also read that processor speed is obviously important. Hence I am looking at the 7700k at 5ghz

I cannot overclock my self and the above clock speeds are the maximum that Scan.co.uk will supply for these chips so I am just wondering if anyone knows which chip would give the best FPS / performance in P3D at the following clock speeds?

4 core I7 7700k @5Ghz or 8 core I7 7820X @4.6Ghz ?

Thanks in advance

 

Keithy

I'd also like to hear the community's thoughts about this.  Bit of a muddy time with Intel products... only the 7700K seems to have solid footing at the moment.  AMD's Threadripper seems to have some chops as well, but it's real benefit seems to be with multi-threaded production-type applications, not gaming [heavy single-threaded games].  Maybe a bit early to fully understand all that.

But, for those of us on the verge of building new flight sim PCs, its a bit dodgy right now, so comments on this topic would be good to hear.

A quick chime in ...

I've not seen any "single thread" performance numbers in regards to AMD 1920X or 1950X.  I've seen multi-thread numbers vs. the 7900X, but considering the 6+ core advantage of AMD has over the 7900X I wasn't impressed ... which signals that single thread performance on the AMD CPU is not as good as Intel's and it's still a dual bank design.  For P3D, single thread execution performance is important, 8-16 cores is much less important.

I currently have no evidence that more than 4 "real" cores is better.  Going from 4.6Ghz to 5.0Ghz will only net about 2-3 FPS assuming peak loads around 30 FPS and assuming CPU limited and not GPU limited.  In P3D V4 it's relatively easy to shift CPU/GPU utilization balance from CPU to GPU or from GPU to CPU ... dense populated area and high AI traffic levels will produce higher CPU, Dynamic Lights, Dynamic Reflections and SSAA will produce higher GPU ... both at the same time will produce lots of HEAT (this is where a good water cooling solution helps).

As far as Cache size relative to my old 5960X, the 7900X is: 

5960X L3 = 20MB (single shared)
7900X L3 = 13.75MB (single shared)
5960X L2 = 256KB (per core) 
7900X L2 = 1MB (per core)
5960X L1 = 32KB (Instruction per core) + 32KB (data per core) 
7900X L1 = 32KB (Instruction per core) + 32KB (data per core)

So overall the 7900X combine caches is about 27.5MB with the 5960X at 22.5MB ... Intel seemed to believe it was more important to increase the L2 Cache size while reducing the single shared cache for better performance.  I have no evidence to agree or disagree.

Keep in mind 5960X is 8 CORE, 7900X is 10 CORE.

My 7900X is definitely performing better than my 7700K at the same 4.8Ghz in terms of P3D performance (once I disabled Intel's Turbo Boost Max Technology) ... so I would imagine the 7820X would be a better cost effective option for the same level of performance as the 7900X.  But don't expect miracles, if you load up every add-on imaginable, in a dense location like KSEA, with graphics settings maxed out, at 4K res and high levels of SSAA then you'll still be below 30 FPS.

Cheers, Rob.

EDIT: some trivia, AMD 1950X LN2 OC max was 5.2Ghz, Intel 7900X LN2 OC max was 6.0Ghz

Don't buy now. Wait for Coffee Lake. The 8700K will be presented on August, 21st. The wait should be worth it from what I have read. 

I agree with Carlito777

 

On 09/08/2017 at 4:59 AM, carlito777 said:

Don't buy now. Wait for Coffee Lake. The 8700K will be presented on August, 21st. The wait should be worth it from what I have read. 

Yup, 8700K will be the bee's knees. Don't waste a single dollar on that awful X299 platform. 

No wait, 

Intel also recently introduced new Kaby Lake-X and Skylake-X processors, both of which comprise its Core-X series. These are intended for enthusiasts who want added performance, which Intel delivers in the form of more cores, more threads, more cache, more PCI-Express lanes, and expanded memory support.

Another milestone for 10nm: Cannon Lake on track and we’ve now taped in Ice Lake, our 2nd-generation 10nm product. pic.twitter.com/DUDm3MsBaB

— Intel Official News (@intelnews) June 8, 2017

And of course there is Cannon Lake. That is the big one that everyone is waiting for, as it will Intel's first processor family to be built on a 10nm manufacturing process. Cannon Lake will reportedly deliver a 25 percent performance boost compared to Kaby Lake, while offering a 45 percent reduction in power consumption. Cannon Lake processors are expected to arrive by the end of the year.

10 hours ago, Noel said:

No wait, 

Intel also recently introduced new Kaby Lake-X and Skylake-X processors, both of which comprise its Core-X series. These are intended for enthusiasts who want added performance, which Intel delivers in the form of more cores, more threads, more cache, more PCI-Express lanes, and expanded memory support.

Another milestone for 10nm: Cannon Lake on track and we’ve now taped in Ice Lake, our 2nd-generation 10nm product. pic.twitter.com/DUDm3MsBaB

— Intel Official News (@intelnews) June 8, 2017

And of course there is Cannon Lake. That is the big one that everyone is waiting for, as it will Intel's first processor family to be built on a 10nm manufacturing process. Cannon Lake will reportedly deliver a 25 percent performance boost compared to Kaby Lake, while offering a 45 percent reduction in power consumption. Cannon Lake processors are expected to arrive by the end of the year.

Cannon Lake will most likely only be released next year with the mobile CPUs released first. So the desktop variants will most likely not be released earlier than in the second half of 2018. So it doesn't really make sense to wait for that. But waiting for Coffee Lake which will be released in the next couple of weeks is certainly worth it. 

6 hours ago, carlito777 said:

Cannon Lake will most likely only be released next year with the mobile CPUs released first. So the desktop variants will most likely not be released earlier than in the second half of 2018. So it doesn't really make sense to wait for that. But waiting for Coffee Lake which will be released in the next couple of weeks is certainly worth it. 

I'm waiting as long as my now reborn 3930K lives on and with any luck could make it to mid 2018 and beyond.  I'd love to see better thermal performance as the current CPUs seem pretty wretched in that regard, and who knows maybe 'Icelake' will meet that expectation.

1 hour ago, Noel said:

I'm waiting as long as my now reborn 3930K lives on and with any luck could make it to mid 2018 and beyond.  I'd love to see better thermal performance as the current CPUs seem pretty wretched in that regard, and who knows maybe 'Icelake' will meet that expectation.

Of course, if you don't have any immediate need for a new PC then it could be worth it to wait for the 10nm generation. My CPU died two weeks ago so I currently have no simming PC which is really tough (first world problems... ;-) ). But I'm not jumping onto a 7700K right away but will wait for the 8700K as this will at least give me 6 cores at a small extra cost (if any). 

2 hours ago, carlito777 said:

Of course, if you don't have any immediate need for a new PC then it could be worth it to wait for the 10nm generation. My CPU died two weeks ago so I currently have no simming PC which is really tough (first world problems... ;-) ). But I'm not jumping onto a 7700K right away but will wait for the 8700K as this will at least give me 6 cores at a small extra cost (if any). 

Well, I was in your boat until ASUS sent me a refurbished P9X79 WS for a grand total of $140 and I was able to plug and play to complete restoration of   my entire install and a second OS install for non FS stuff, so I was tickled pink.    I am getting the same easy overclock w/ fabulous core temps.  I hope it lasts until thermal management improves as well as high single core performance.  I wouldn't mind 8+ cores for a bit more of future proofing.  As I see it it's GPU and multithreading that are where real improvement are to be had going forward.

FYI, looks like the gaming and single thread performance numbers are starting to trickle in for AMD's Threadripper (1920X and 1950X) and a I suspected single thread performance is still NOT good on the AMD front (in some tests almost 50% lower than Intel).  AMD will make for a good video/3D rendering PC, but not a great choice for gaming/flight simulation and it's overclocking potential is low relative to Intel.

The 8700K seems like it will be a good price/performance ratio and "stock" can run 4.6Ghz boost, so figure hitting 5Ghz should be relatively easy ... the onboard graphics is just a waste of space that could be better used for larger Cache sizes ... not sure why Intel keep pushing their on chip graphics for desktop focus CPUs, makes NO SENSE.

Cheers, Rob.

 

7700k here running at 5.1GHz in P3D v4 with a GTX 1080 Ti and couldn't be happier. Performance is astonishing, even at high slider settings (I use Rob's P3Dwiki as a starting guideline) - even at lower FPS (below 30FPS) performance is smooth. I'm so glad I went for the 7700k over an AMD Ryzen with more cores. Single core performance is still king it seems and I've never had such good sim performance (not to mention more OOMs).

9 hours ago, JamesIceland said:

(I use Rob's P3Dwiki as a starting guideline)

You got a link to this?

45 minutes ago, Charlatan said:

You got a link to this?

Sure - www.p3dwiki.com

Rob has an excellent range of settings for different circumstances on there which I have set up as profiles in SimStarterNG and tweaked for my own personal system. That said, I am using about 90% of what he outlines on there with really good results and switching between the settings depending on what I fly.

Last night I flew the PMDG 777 using his Com City Day settings with a couple of sliders one step further to the right (traffic etc) and had a great flight from CYVR to KSFO over Orbx Regions using FSDT's CYVR and FlightBeams new KSFOHD2 - this was a notoriously difficult route for me on my old set up (not including the guaranteed OOM's I'd get) but last night I got smooth performance with beautiful scenery.